Although takotsubo cardiomyopathy is often referred to as "broken heart syndrome" because of its occurrence in response to strongly negative emotions, such as grief or intense anger, new research suggests that positive emotions can also sometimes act as a trigger.

Not surprisingly, most of the 485 patients assessed from the International Takotsubo (InterTAK) Registry experienced a preceding negative emotional event (96%). However, the other 4% of these patients had had a pleasant occurrence.

The one difference came in midventricular involvement, with ad hoc analysis showing a significantly higher prevalence in the joyful-events group vs the negative-events group (P=0.03).

Ghadri told heartwirefrom Medscape that the findings "may lead to a paradigm shift" in clinical practice. "Physicians need to be aware that even positive stressors might bear a certain risk for an acute cardiac disease. And these patients should be regarded seriously if presenting in the emergency department," she said via email.

The findings were published online earlier this month in the European Heart Journal.

Overstimulated Nervous System

"It is well-known that emotional distress may result in an overstimulation of the sympathetic nervous system and/or inappropriate parasympathetic withdrawal," write the researchers, adding that this can result in arrhythmias, sudden cardiac death, or takotsubo syndrome (TTS).

However, what role positive emotions may play "is far less clear." In the worst birthday-gift news ever, they note that some type of CV event is 27% more likely to occur on one's birthday than on any other day.

The InterTAK Registry was created at University Hospital Zurich in 2011 and includes patient records from participating centers located in nine countries, including the US. Of the 1750 patients registered between 2011 and 2014, 485 had had a preceding emotional occurrence. This latter group was the focus of the current study.

Women made up the majority of both the "happy-heart" group (95.0%) and the "broken-heart" group (94.6%). The mean ages for each group was 71 and 65 years, respectively (P=0.03).

Events reported by the happy-heart group prior to their presentation included birthday and family parties, family weddings, unexpected visits, a win for a favorite sports team, and pleasant anticipation before a special anniversary or reunion.

There were no significant between-group differences for "symptom onset to hospitalization within the first 24 hours" (100% vs 85%, respectively). There were also no differences in ECG-diagnosed ST-segment elevation (50% vs 45%), ST-segment depression (15% vs 6%), T-wave inversion (45% vs 40%), and left bundle branch block (5% vs 5.1%). In addition, 95% and 94%, respectively, were in sinus rhythm; and 5% and 5.5% had atrial fibrillation.

"For the first time, we present a systematic analysis of patients diagnosed with TTS after joyful or socially desirable events, contrary to the well-established literature," write the investigators.

"Despite their distinct nature, happy and sad life events may share similar final common emotional pathways, which can ultimately trigger TTS," they note, adding that the study may provide "important insights into the brain-heart interaction."

Ghadri reported that she contributed to a study published last year in the New England Journal of Medicine that showed that TTS is associated with substantial mortality and morbidity. "Therefore, cardiac care in the acute phase [of this syndrome] is of utmost importance, since patients can die," she warned.

The study was funded by grants from the Mach-Gaensslen Foundation, the Olten Heart Foundation, the Professor Otto-Beisheim-Foundation, the Swiss Heart Foundation, and the University of Zurich. The authors report no relevant financial relationships.